Comparative proteomic analysis of outer membrane protein 43 (43)-deficient .

Outer membrane proteins (OMPs) of Gram-negative bacteria constitute the first line of defense protecting cells against environmental stresses including chemical, biophysical, and biological attacks. Although the 43-kDa OMP (OMP43) is major porin protein among -derived OMPs, its function remains unreported. In this study, OMP43-deficient mutant (Δomp43) was generated to investigate OMP43 function. Interestingly, Δ43 exhibited weaker proliferative ability than that of wild-type (WT) . To study the differences in proteomic expression between WT and Δ43, two-dimensional gel electrophoresis-based proteomic analysis was performed. Based on Clusters of Orthologus Groups functional assignments, 12 proteins were associated with metabolism, 7 proteins associated with information storage and processing, and 3 proteins associated with cellular processing and signaling. By semi-quantitative reverse transcriptase polymerase chain reaction, increases in D, X, A, B, and ATPA mRNA expression and decreases in and A mRNA expression were confirmed in Δ43. In conclusion, this is the first report showing that a loss of OMP43 expression in leads to retarded proliferation. Furthermore, our proteomic data provide useful information for the further investigation of mechanisms related to the growth of